Intelligent Window Heat Control System

ABSTRACT

A system for monitoring performance of an aircraft windshield includes a sensor comprising a sensory contact and an evaluation unit. The sensory contact is in physical contact with one or more components of the windshield, and generates a signal representative of the performance of the component(s) of the windshield. An electrical connector is secured to the surface of the windshield facing the interior of the aircraft. The signal from the sensory contact passes through the connector to the evaluation unit. The evaluation unit acts on the signal to determine the performance of the component(s) of the windshield, wherein the evaluation unit is spaced from and out of physical contact with the windshield and the electrical connector, and is in electrical contact with the electrical connector.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to an intelligent window heat control system fora vehicle, e.g., but not limited to an aircraft, and more particularly,to a control sensor or sensor system for an aircraft including, amongother things, a sensor that is physically attached to the measurementcomponent or target, and a sensor evaluation unit that providesintelligent data processing to arrive at a conclusion or measurementresult of the performance of an article of the aircraft, e.g., but notlimited to a heatable member of an aircraft windshield, and optionallyto take action to alter current flow to the heatable member based on themeasurement result.

2. Presently Available Technology

At the present time, windows or transparencies for vehicles, e.g., butnot limited to windshields for aircrafts, have sensors to determineperformance of the windshield and a control system to take action whenthe performance of the windshield is operating outside of acceptableoperating limits to prevent damage to the windshield. A detaileddiscussion of transparencies, e.g., but not limited to aircraftwindshields having sensors and control systems, is disclosed in U.S.Pat. Nos. 8,155,816; 8,383,994; and 8,981,265. U.S. Pat. Nos. 8,155,816and 8,383,994 in their entirety are hereby incorporated by reference.

For purposes of this invention, the sensors operating on an article,e.g., but not limited to a windshield, are considered to include twocomponents or sub-operating systems. For purposes of clarity, onecomponent or sub-operating system of the sensor is referred to as the“sensory portion” of the sensor, and the second component or secondsub-operating system is referred to as the “evaluation unit” of thesensor. The sensory portion is effected by the changes to the article orcomponent under observation, e.g., but not limited to heating theheatable member of a windshield to remove snow, ice, and fog from theouter surface of the windshield, and the sensory portion forwards asignal, usually but not limited to an electric signal, to the evaluationunit. The evaluation unit acts on the signal from the sensory portion tomonitor the operating condition of the article or component, andforwards a signal, usually an electric signal, representing theoperating condition of the article to a control system.

When the article is operating within acceptable limits, it is expectedthat the sensory portion, and/or the evaluation unit, indicates that noaction is to be taken; however, when the article is operating outside ofacceptable limits, action is taken by the heater controller, e.g., butnot limited to disconnecting the heatable member and its electricalpower source from one another, to prevent damage to the windshieldand/or the aircraft.

One of the limitations of the presently available system is that thesensory portion, and the evaluation unit, are mounted on the article,e.g., but not limited to a windshield, being monitored. Although thepresent practice is acceptable, there are limitations. Moreparticularly, each windshield must have a sensory portion mounted on thearticle with the evaluation unit also mounted on the article. As can nowbe appreciated, it would reduce the cost of the windshield if theperformance measuring portion of the sensor was mounted on the aircraftinstead of the windshield. Additionally, in some cases it may bepossible to monitor the status of the article without a sensory portionconnected to the article using remote measurement methods. In thismanner, an evaluation unit mounted on the aircraft can be assigned toservice a particular windshield position, and the sensory portion of awindshield mounted in the particular windshield position is connected tothe performance measuring portion assigned to service the particularwindshield position. With the above arrangement, the need to provideeach windshield with an evaluation unit is eliminated.

SUMMARY OF THE INVENTION

This invention relates to a system for monitoring performance of anarticle, or a component of an article of a vehicle, the system includesa sensor including a sensory contact and a sensory performanceevaluation unit. The sensory contact is in physical contact with thearticle or the component of the article, and generates a signalrepresentative of the performance of the article or the component of thearticle, wherein the evaluation unit acts on the signal to determine theperformance of the article or the component of the article. The sensoryperformance evaluation unit is spaced from, and out of physical contactwith, the article and the electrical connector.

The invention further relates to an improved aircraft windshield of thetype having a sensor. The sensor includes a sensory contact acting on acomponent of the windshield and an evaluation unit, wherein the sensorycontact is in physical contact with the component of the windshield, andgenerates a signal representative of the performance of the component ofthe windshield. The signal is acted on by the evaluation unit of thespacer to determine the performance of the component of the windshield,wherein the sensory performance evaluation unit is in physical contactwith the windshield and is in electrical contact with the sensorycontact. The improvement includes, but is not limited to the evaluationunit spaced from and out of physical contact with the windshield, and inelectrical contact with the electrical connector, and the sensorycontact of the spacer.

The invention still further relates to a transparency for a vehicleincluding, among other things, a heatable member including, among otherthings, an electric heatable film, a pair of spaced bus bars on theheatable film and wires connecting the bus bars to switches and electricpower, wherein when selected switches are in the closed positions,current moves through the bus bars to heat the film and, when selectedones of the switches are in the open position, there is no currentmoving through the bus bars. Electrical wires are connected to thecircuit and extending out of the transparency to provide externalelectrical access to the circuit; and a sensor electrically to an end ofthe wires, wherein the sensor moves the selected ones of the switch tothe open position when arcing above an electrical level is detected andto set the selected switches in the closed position when no arcing isdetected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an aircraft having non-limitingembodiments of the invention.

FIG. 2 is a cross-sectional view of an aircraft transparencyincorporating features of the invention.

FIG. 3 is an isometric view of a heatable member of the aircrafttransparency of FIG. 2 showing in block diagram an electrical systemused in the practice of the invention to determine arcing of a heatingarrangement.

FIG. 4 is a plan view of a non-limiting aspect of a sensory portion ofan impact sensor or detector positioned on the electrically conductivemember of a heating arrangement in accordance to the teachings of theinvention.

FIG. 5 is a non-limiting aspect of an electrical system of theevaluation unit or performance measuring portion of the impact sensorsto measure performance of the sensory portion of the impact sensor inaccordance to the teachings of the invention, the sensory portion of theimpact sensor shown in FIG. 4.

FIG. 6 is a schematic view of a non-limiting aspect of a rupture sensoror detector of the invention.

FIG. 7 is a view taken along lines 7-7 of FIG. 6.

FIG. 8 is a schematic view of another non-limiting aspect of a sensoryportion of a rupture sensor or detector used in the practice of theinvention.

FIG. 9 is a plan view of a non-limiting aspect of a sensory portion of amoisture sensor or detector positioned over the electrically conductivemember of a heating arrangement in accordance to the teachings of theinvention.

FIG. 10 is a view taken along lines 10-10 of FIG. 9.

FIG. 11 is a non-limiting aspect of an electrical system of theinvention to monitor and act on output signals of the sensory portion ofthe moisture sensors shown in FIG. 9 in accordance to the teachings ofthe invention.

FIG. 12 is a non-limiting aspect of an electrical system of theperformance measurement portion of the moisture sensors shown in FIG. 9in accordance to the teachings of the invention.

FIG. 13 is a block diagram of a non-limiting aspect of an intelligentelectrical power controller and monitoring system of the inventionconnecting an electrical power supply of the aircraft to the heatingarrangement of the type shown in FIG. 3.

FIG. 14 is a block diagram of a non-limiting embodiment of an arcmonitoring system of the invention showing the sensory portion and theevaluation unit of the arc sensor.

FIG. 15 is a view of a heating arrangement showing the sensory portionand the evaluation unit of the impact sensor, rupture sensor, moisturesensor, temperature sensor, and arc sensor.

FIG. 16 is an isometric view of a windshield of the prior art showingconnectors on the inner surface of windshield to connect electric powerand electrical equipment discussed herein to the impact sensor, rupturesensor, moisture sensor, temperature sensor, and arc sensor, and tomonitor several aspects of the heating arrangement.

FIG. 17 is a view similar to the view of FIG. 16 showing the sensoryportion of the impact sensor, rupture sensor, moisture sensor,temperature sensor, and arc sensor connected to the evaluation unit ofthe impact sensor, rupture sensor, moisture sensor, temperature sensorand arc sensor in accordance to the teachings of the invention.

FIG. 18 is an elevated front view of a housing having a healthmonitoring system for the aircraft, the health monitoring systemincorporating, among other things, features of the invention to monitorperformance of selected components of a transparency, e.g., but notlimited to an aircraft windshield, by, among other things, monitoringthe evaluation unit of the impact sensor, rupture sensor, moisturesensor, temperature sensor, and arc sensor in accordance to theteachings of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, spatial or directional terms such as “inner”, “outer”,“left”, “right”, “up”, “down”, “horizontal”, “vertical”, and the like,relate to the invention as it is shown in the drawing on the figures.However, it is to be understood that the invention can assume variousalternative orientations and, accordingly, such terms are not to beconsidered as limiting. Further, all numbers expressing dimensions,physical characteristics, and so forth, used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical values set forth in the following specification and claims canvary depending upon the property desired and/or sought to be obtained bythe present invention. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Moreover, all ranges disclosed herein are to beunderstood to encompass any and all subranges subsumed therein. Forexample, a stated range of “1 to 10” should be considered to include anyand all subranges between and inclusive of the minimum value of 1 andthe maximum value of 10; that is, all subranges beginning with a minimumvalue of 1 or more and ending with a maximum value of 10 or less, e.g.,1 to 6.7, or 3.2 to 8.1, or 5.5 to 10. Also, as used herein, the term“positioned over” or “mounted over” means positioned on or mounted overbut not necessarily in surface contact with. For example, one article orcomponent of an article “mounted over” or positioned over” anotherarticle or component of an article does not preclude the presence ofmaterials between the articles, or between components of the article,respectively.

Before discussing non-limiting embodiments of the invention, it isunderstood that the invention is not limited in its application to thedetails of the particular non-limiting embodiments shown and discussedherein since the invention is capable of other embodiments. Further, theterminology used herein to discuss the invention is for the purpose ofdescription and is not of limitation. Still further, unless indicatedotherwise in the following discussion, like numbers refer to likeelements.

A non-limiting embodiment of the invention will be directed to anaircraft, e.g., but not limited to the aircraft 10 shown in FIG. 1; andto the transparencies of the aircraft, e.g., but not limited to aircraftwindshields 14 having sensors discussed in detail below to provideinformation regarding the performance of the transparencies and takeappropriate action to avoid damage to the aircraft and aircraftcomponents. The invention, however, is not limited to any particulartype of sensor, aircraft, and/or aircraft transparency, and theinvention can be practiced on any type of aircraft and/or aircrafttransparency using any design of sensors to measure performance of thetransparency. Further, the invention can be practiced on commercial andresidential windows, e.g., but not limited to the type disclosed in U.S.Pat. No. 5,675,944; a window for any type of land vehicle; a canopy,cabin window, and windshield for any type of air and space vehicle, awindow for any above or below water vessel, and a window for a viewingside or door for any type of containers, for example but not limited toa refrigerator, cabinet, and/or oven door.

The windshield 14 is preferably a laminated windshield have sensorsdiscussed in detail below and discussed in U.S. Pat. No. 8,383,994.Shown in FIG. 2 is a non-limiting embodiment of the cross section of theaircraft windshield 14 that can be used in the practice of theinvention. The windshield 14 includes a first glass sheet 22 secured toa second glass sheet 24 by a first vinyl-interlayer 26; the second sheet24 secured to a second vinyl-interlayer 28 by a first urethaneinterlayer 30, and the second vinyl-interlayer 28 secured to a heatablemember or heating arrangement 32 by a second urethane interlayer 34.

An edge member or moisture barrier 36 of the type used in the art, e.g.,but not limited to a silicone rubber or other flexible, durable,moisture resistant material, is secured to (1) peripheral edge 38 of thewindshield 14, i.e., the peripheral edge 38 of the first and secondglass sheets 22, 24; of the first and second vinyl-interlayers 26, 28;of the first and second urethane interlayers 30, 34 and of the heatablemember 32; (2) margins or marginal edges 40 of inner surface 42 of thewindshield 14, i.e., the margins 40 of the outer surface 42 of the firstglass sheet 22 of the windshield 14; and (3) margins or marginal edges44 of outer surface 46 of the windshield 14, i.e., margins of the outersurface 46 of the heatable member 32.

As is appreciated by those skilled in the art and not limiting to theinvention, the first and second glass sheets 22, 24; the first andsecond vinyl-interlayers 26, 28; and the first urethane interlayer 30form the structural part, or inner segment, of the windshield 14 and theouter surface 42 of the windshield 14 faces the interior of the aircraft10 (see FIG. 1). The second urethane layer 34 and the heatable member 32form the non-structural part, or outer segment, of the windshield 14,and the outer surface 46 of the windshield 14 faces the exterior of theaircraft 10. The heatable member 32 provides heat to remove fog from,and/or to melt ice on, the outer surface 46 of the windshield 14 in amanner discussed below.

As can be appreciated, the invention is not limited to the constructionof the windshield 14 and any of the constructions of aircrafttransparencies used in the art can be used in the practice of theinvention. For example and not limited to the invention, the windshield14 can include a construction wherein the second vinyl-interlayer 28 andthe first urethane interlayer 30 are omitted, and/or the glass sheets 22and 24 are plastic sheets.

Generally, the glass sheets 22 and 24 of the windshield 14 are clear,chemically strengthened glass sheets; however, the invention is notlimited thereto, and the glass sheets 22 and 24 can be heat strengthenedor heat tempered glass sheets. Further, as is appreciated by thoseskilled in the art, the invention is not limited to the number of glasssheets 22 and 24, vinyl-interlayers 26 and 28, or urethane interlayers30 and 34 that make up the windshield 14, and the windshield 14 can haveany number of sheets and/or interlayers.

The invention is not limited to the design and/or construction of theheatable member 32, and any electrical conductive heatable member usedin the art to heat a surface of a sheet to prevent the formation of fog,snow, and/or ice on, to melt snow and ice on, and/or to remove fog,snow, and ice from, the outer surface of a windshield, e.g., but notlimited to the outer surface 46 of the windshield 14, can be used in thepractice of the invention. With reference to FIG. 3, in one non-limitingembodiment of the invention, the heatable member 32 includes a glasssheet 60 (also referred to as a third glass sheet 60) having aconductive coating 62 applied to surface 64 of the third glass sheet 60,and a pair of spaced bus bars 66, 68 in electrical contact with theconductive coating 62. More particularly, the conductive coating 62 isbetween and in electrical contact with the bus bars 66, 68. Theinvention is not limited to the composition of the conductive coating62, and any of the electrical conductive coatings known in the art canbe used in the practice of the invention. For example, and not limitingto the invention, the conductive coating 62 can be made from anysuitable transparent electrical conductive material. Non-limitingembodiments of transparent conductive coatings 62 that can be used inthe practice of the invention include, but are not limited to, apyrolytic deposited fluorine doped tin oxide film of the type sold byPPG Industries, Inc. under the registered trademark NESA; a magnetronsputter deposited tin doped indium oxide film of the type sold by PPGIndustries, Inc. under the registered trademark NESATRON; a coating madeup of one or more magnetron sputter deposited films, the filmsincluding, but not limited to a metal film, e.g., silver between metaloxide films, e.g., zinc oxide and/or zinc stannate, each of which can beapplied sequentially by magnetron sputtering, e.g., as disclosed in, butnot limited to, U.S. Pat. Nos. 4,610,771; 4,806,220; and 5,821,001. Thedisclosures of U.S. Pat. Nos. 4,610,771; 4,806,220; and 5,821,001 intheir entirety are hereby incorporated by reference.

The invention is not limited to the use of an electrical conductivecoating 62 to heat the third glass sheet 60, and the inventioncontemplates the use of any type of member that can be electricallyheated, e.g., but not limited to electrical conducting wires. The wires,e.g., wires 69 shown in phantom in FIGS. 2 and 3, can be embedded in asheet of a plastic interlayer, e.g., but not limited to the secondurethane interlayer 34 between the bus bars 66 and 68, and electricallyconnected to the bus bars 66 and 68. Such a heating arrangement is knownin the art under the PPG Industries Ohio, Inc. registered trademarkAIRCON and is disclosed in U.S. Pat. No. 4,078,107, which patent in itsentirety is incorporated herein by reference.

The invention is not limited to the design and/or construction of thebus bars 66 and 68, and any of the types of bus bars used in the art canbe used in the practice of the invention. Examples of bus bars that canbe used in the practice of the invention include, but are not limitedto, the types disclosed in U.S. Pat. Nos. 3,762,902; 4,623,389; and4,902,875, which patents in their entirety are hereby incorporated byreference.

With continued reference to FIG. 3, in one non-limiting embodiment ofthe invention, each of the bus bars 66 and 68 are connected by a wire 70and 71, respectively, to an intelligent electrical power controller andmonitoring system 72 (discussed in more detail below), and thecontroller and monitoring system 72 is connected to aircraft electricalpower supply 74 by wires or electric cables 76 and 77. Although notlimiting to the invention, ends 79 of the bus bar 66, and ends 80 of thebus bar 68 are spaced from adjacent sides 82-85 of the glass sheet 60,and sides 86 of the coating 62 are spaced from the sides 82-85 of theglass sheet 60, to prevent arcing of the bus bars 66 and 68, and thecoating 62 with metal body cover 87 of the aircraft 10 (see FIG. 1).

In a non-limiting embodiment of the invention, the windshield 14 isprovided with one or more sensors to monitor the performance of selectedcomponents and/or properties of the windshield 14. In this aspect of theinvention, the sensors include, but are not limited to: an impactsensor; a rupture sensor; a moisture sensor; a conductive coatingtemperature sensor; and an arc sensor.

As discussed above and repeated here for purposes of appreciating theinvention, the sensors operating on an article or component, e.g., butnot limited to the heatable member 32 of the windshield 14, areconsidered to include two sub-operating systems. For purposes ofclarity, one component or sub-operating system of the sensor is referredto as the “sensory portion” of the sensor, and the second component orsecond sub-operating system is referred to as the “evaluation unit” ofthe sensor. The sensory portion is used as a feed back to the evaluationunit to trigger the control actions on a component or article of theaircraft, e.g., but not limited to the heatable member 32 of thewindshield 14, to, among other things, increase or decrease the heat ofthe heatable member 32 through the supplied electrical current to theheatable member 32. For example, the windshield temperature sensors(discussed in detail below) are used to monitor the heatable member 32effected by the changes to the article or component under observation,e.g., but not limited to heating the heatable member 32 of a windshield14 to remove snow, ice, and/or fog from the outer surface 36 of thewindshield 14, and the sensory portion forwards a signal, usually, butnot limited to an electric signal, to the evaluation unit to trigger acontrol action on the amount of heat (electrical current) applied to theheatable member of the windshield.

The evaluation unit acts on the signal from the sensory portion tomeasure the properties of the article, e.g., but not limited to thetemperature of the heatable member, as an indication of actualperformance and/or potential windshield failures and/or as an indicationfor a preventive maintenance for the windshield article or component,e.g., but not limited to the heatable member of the windshield. In oneaspect of the invention, the signals from the evaluation unit isforwarded to an electronic storage (electric storage 266, FIG. 14,discussed in more detail below) to compile a history of the performanceof the article being monitored, e.g., but not limited to the windshieldof the aircraft.

In another non-limiting aspect of the invention, the sensors areconsidered to be “activating sensors” or “non-activating sensors.”“Activating sensors” are sensors in which the evaluation unit istriggered to take action when the article or component, e.g., but notlimited to the heatable member of the windshield, forwards a signalindicating that the heatable member is operating outside of acceptablelimits. The action can include, but is not limited to, the evaluationunit acting on the article or component to separate the article orcomponent from the power supply and/or modifying the power input to thearticle or component, to change the operating performance of the articleor component being monitored. By way of illustration and not limiting tothe invention, an arc sensor monitors the performance of the heatablemember 32. When the evaluation unit determines electric arcing isoccurring, a signal is forwarded to the electronic storage (electricstorage 266, FIG. 14, discussed in more detail below) and to a powersupply switch (198, FIG. 13) to electrically separate the heatablemember and the current supply to stop heating the outer surface of thewindshield. “Non-activating sensors” are sensors in which the sensoryportion forwards a signal, e.g., but not limited to an electric signalto the electronic storage and to a display (housing 400, FIG. 18,discussed in more detail below) to advise responsible personnel that thecomponent being monitored is operating inside or outside of acceptablelimits. By way of illustration and not limiting to the invention, amoisture sensor monitors moisture moving between the interlayers of thelaminated windshield. When the signal from the evaluation unit of themoisture sensor indicates undesirable levels of moisture, no action istaken. Instead, responsible personnel are advised to take action, wherethe action taken can include, but is not limited to, schedule thewindshield for replacement and/or repair. In another non-limitingexample of the invention, an impact sensor monitors impacts to thewindshields. When the signal from the evaluation unit of the impactsensor indicates undesirable levels or numbers of impacts, thewindshield is examined after the aircraft has landed to determine if thewindshield is structurally useable.

More particularly, when the signal from the evaluation unit acts toinform those who have a need to know, e.g., but not limited to theoperators of the aircraft, that a component is operating outside ofacceptable limits, but does not act to shut down or limit the operationof the component, the sensor is acting as a non-activating sensor. Whenthe signal from the evaluation unit acts to shut down or limit theoperation of the component, and optionally inform those that have a needto know, e.g., but not limited to the operators of the aircraft, thatthe component is operating outside of acceptable limits, the sensor isacting as an activating sensor.

The discussion is now directed to the operation of selected sensorsusually found on a windshield of an aircraft for a better appreciationand understanding of (1) the sensory portion, and the evaluation unit;(2) the use of the sensor as a “non-activating sensor” and/or as an“activating sensor”; and (3) the positioning of the evaluation unit in alocation other than the component having the sensory portion. Thesensors discussed below include, but are not limited to, an impactsensor, a rupture sensor, a moisture sensor, an arc sensor, and aconductive coating temperature sensor. A discussion of the sensors ispresented in the non-limited aspects of the invention discussed below,and a detailed discussion is found in U.S. Pat. Nos. 8,155,816;8,383,994; 8,981,265; and 9,166,400. As can be appreciated, theinvention is not limited to the sensors discussed below, and theinvention can be practiced with any type of sensor, e.g., but notlimited to stress sensor, p-static sensor.

Impact Sensor

As can be appreciated, the invention is not limited to the design orconstruction of the impact sensor and any impact sensor used in the artcan be used in the practice of this invention. In one non-limitingaspect of the invention, the heatable member 32 of the windshield 14, asshown in FIG. 4, is provided with four impact sensors or detectors 89a-89 d. Each of the four impact sensors 89 a-89 d includes a sensoryportion 91 a-91 d (see FIG. 4) and an evaluation unit 93 a-93 d (seeFIG. 5), respectively. The sensory portion 91 a-91 d of the impactsensors 89 a-89 d, respectively, are mounted on a sheet of thewindshield 14. In FIG. 4 the sensory portion 91 a-91 d of the sensors 89a-89 d are mounted on or over the surface 64 of the sheet 60 of theheatable member 32 and, more particularly, but not limiting to, theinvention on the conductive coating 62 of the heatable member 32. Thesensors 89 a-89 d indicate that one or more foreign objects have hit theouter surface 46 of the windshield 14 and of the heatable member 32 (seeFIG. 3), and optionally the sensors 89 a-89 d report the location on theouter surface 46 where the hit or impact occurred and the relativeenergy of the impact on the surface 46 of the windshield 20.

The sensory portion 91 a-91 d of each of the impact sensors 89 a-89 dincludes a piezoelectric crystal. When the piezoelectric crystal isexposed to vibration, e.g., vibration of the glass sheet 60 (see FIGS. 1and 2) caused by a stone hitting the outer surface 46 of the glass sheet60, the piezoelectric crystal undergoes a compression or distortion and,as a result, produces an electric field, which can be used to activateor to cause an alarm and/or a recorder to be activated to announceand/or record the hit or impact.

With continued reference to FIGS. 4 and 5, the sensory portion 91 a-91 dof the impact sensors 89 a-89 d are in electrical contact with ones ofpiezoelectric crystals by a connection 95 a-95 d. Each of the impactsensors 89 a-89 d are electrically connected to data processingequipment 99 and the power supply 74 by way of wires 102 a-102 d,respectively (see FIG. 5). In this manner, the power to the impactsensors 89 a-89 d is provided by the power supply 74, and changes in theelectric field of each of the impact sensors 89 a-89 d measured ormonitored by the data processing equipment 99. As can be appreciated,the invention is not limited to the manner in which electric power isprovided to the impact sensors 89 a-89 d and any circuit arrangement canbe used in the practice of the invention. As can be appreciated, thepower input to the impact sensors can be a power input to the evaluationunit of the sensor and the power supply can be alternating or directcurrent.

In one non-limiting aspect of the invention, the data processingequipment 99 is software which analyzes the signal forwarded along wires97 a-97 d and 102 a-102 d to determine the location of the impact bytriangulation of the signals from selected ones or all of the sensors 89a-89 d, and the magnitude of the impact, e.g., by the magnitude of theelectric field, and stores the information. Electronic circuitry for useof impact detectors, e.g., piezoelectric crystal is well known in theart, e.g., see U.S. Pat. No. 6,535,126, which patent in its entirety ishereby incorporated by reference, and no further discussion is deemednecessary.

As can be appreciated, the invention can be practiced with more or lessthan four impact sensors 89 a-89 d. More particular, increasing thenumber of impact sensors, e.g., using 5, 6, 7, 10, or 20 impact sensorsincreases the accuracy of locating the impact area and the force withwhich the windshield was impacted, and using less than 4, e.g., 1, 2, or3 sensors, decreases the accuracy of locating the impact area and theforce with which the windshield was impacted.

The sensory portion 91 a-91 d of the impact sensors 89 a-89 d,respectively, discussed above includes the piezoelectric crystal(identified by numbers 91 a-91 d in FIG. 4), and the evaluation unit 93a-93 d of the impact sensors 89 a-89 d includes the data processingequipment 99 and electrical connectors, e.g., but not limited to wiresconnecting the electrical components of the sensory portion 93 a-93 d ofthe impact sensors 89 a-89 d.

As can be appreciated, the piezoelectric crystal is not powered byelectric current; however, it is noted that electrical power is requiredto operate the evaluation unit. The electric power supply for theevaluation unit of the impact sensors 89 a-89 d shown in FIG. 5 is theelectric power supply 74 for powering the aircraft 10, however, as canbe appreciated, the evaluation unit or the performance measuring portionof the impact sensors can each be powered by a dedicated power source.

Rupture Sensor

In the following discussion, an aspect of the rupture or crack detector,or sensor disclosed in U.S. Pat. No. 8,383,994, is used in the practiceof the invention, however, as is appreciated, the invention is notlimited thereto and any of the crack sensors or detectors known in theart can be used in the practice of the invention. A non-limiting aspectof a rupture sensor of the type disclosed in U.S. Pat. No. 8,383,994 isshown in FIGS. 6-8 and designated by the numbers 110 (FIG. 6) and 111(FIG. 8). The rupture sensor 110 (FIG. 6) includes an electricallyconductive strip 112 extending along or around substantially the entireouter periphery 38 (see FIGS. 2, 6 and 8) of the major surface 64 of thesheet 60 of the heatable member 62 (see FIG. 6) and/or one of the sheets22, 24 (see FIG. 8) of the windshield 14. In FIGS. 6 and 7, theconductive strip 112 is shown mounted over or in surface contact withthe electrically conductive coating 62 and over or in surface contactwith the surface 64 of the glass sheet 60, surrounds the bus bars 66 and68, and is electrically isolated from the conductive coating 62 and thebus bars 66 and 68 by an electrically insulating layer 114, e.g., aurethane layer or an electrically non-conductive coating layer (see FIG.7).

The conductive strip 112 is mounted over the conductive coating 62spaced from the sides 82-85 of the sheet 60, as shown in FIG. 6. Theconductive strip 112 has a first termination surface 116 and a secondtermination surface 118. The distance or gap between the firsttermination surface 116 and the second termination surface 118 issufficient to prevent any descriptive electrical field communicationbetween the termination surfaces 116 and 118. As can be appreciated, theconductive strip 112 can decrease visibility through that portion of theglass sheet over which it is deposited and, therefore, the maximum widthof the conductive strip 112 depends upon the required or specifiedoperator viewing area through the windshield 14.

As can be appreciated, the conductive strip 112 can be applied to anysurface of any one or all of the sheets of the laminated windshield 14.More particularly, and as shown in FIG. 8, the conductive strip 112 issecured on a surface 119 of the sheet 22 and/or 24 spaced from the outerperiphery 38 of the sheet 22 and/or 24, and the terminal surfaces 116and 118 spaced from one another, as shown in FIG. 8.

The rupture sensor 110 further includes an electrical power source. Thepower source can be the main power source 74 dedicated to providingelectrical power to associated equipment and electronic devices of theaircraft 10 or a dedicated electrical power source identified by thenumber 120 (see FIG. 6) dedicated to powering the electrical components,e.g., but not limited to the conductive strip 112. The dedicated powersource 120 can be any conventional electrical source, such as, but notlimited to, a battery, an electric generator, and the like. Further, therupture sensor 110 includes an electrical measurement mechanism 122,such as an ohmmeter, in communication with the conductive strip 112 formeasuring the electrical condition of the conductive strip 112. Acontrol mechanism 124, such as software and a computer, is used tocontrol and communicate with both the electrical power source 74 and/or120 and the electrical measurement mechanism 122. This control mechanism124 can be used to command the electrical power source 74 and/or 120 toprovide a predetermined or specifically set electrical current to theconductive strip 112 and, after application, the control mechanism 124can collect and/or calculate the electrical potential of the conductivestrip 112 via the electrical measurement mechanism 124.

In an alternative implementation, the electrical power source 74 and/or120 applies a set voltage to the conductive strip 112, as set orspecified by the control mechanism 124. This set voltage allows currentto flow through the conductive strip 112. The electrical measurementmechanism 122 is connected to the conductive strip 112 through a firstlead 126 and a second lead 128. The first lead 126 is connected to thefirst termination surface 116, and the second lead 128 is connected tothe second termination surface 118. This connection allows theconductive strip 112 to act as an electrical circuit when the electricalpower source 74 and/or 120 applies an electrical potential.

The electrical measurement mechanism 122 reads or measures the currentflowing through the conductive strip. Since the electrical power source74 or 120 is applying a set voltage to the conductive strip 112 alonglead 130, and the electrical measurement mechanism 122 is reading ormeasuring the current flowing through the conductive strip 112, theelectrical measurement mechanism 122 (or the control mechanism 124) isable to calculate the resistance value of the conductive strip 112.

When a rupture or crack occurs and propagates in the glass sheet 22, 24,and/or 60, it will eventually reach the conductive strip 112. As thecrack begins to move through and break a section of the conductive strip112, the resistance value calculated by either the electricalmeasurement mechanism 122 or the control mechanism 124 begins toincrease. This resistance value increase indicates a rupture or crack inthe glass sheet and the conductive strip 112, e.g., but not limited tothe glass sheet 22, 24, and/or 60. When the crack fully traverses andbreaks the conductive strip 112, the resistance value reaches infinityand indicates a serious rupture condition.

The conductive strip 112 can be a conductive coating material formedfrom any suitable electrically conductive material, such as a metal,metal oxide, a semi-metal, an alloy, or other composite material. Theconductive strip 112 can also be opaque or transparent. Further, theconductive strip 112 can be a conductive coating material formed from aceramic paint or electrically conductive ink. The conductive material ispreferably a material that will crack or separate when the glass sheetcracks or otherwise change its electrical properties in a manner thatallows for detection of an electrical change. The conductive strip 112can be deposited on a surface of one or more of the glass sheets 22, 24,and 60 through conventional thin film deposit methods or conventionalthick film deposit methods; conventional adhesion manufacturing methods;screening, or other similar process. In one embodiment, the conductivestrip 112 is a conductive indium tin oxide coating.

The invention contemplates a system where the evaluation unit 134 islocated separate from article being monitored. The sensory portion 132of the rupture sensors 110 and 111 include the conductive strip 112, andthe evaluation unit 134 of the rupture sensors 110 and 111 include theelectrical measurement mechanism 122 and the control mechanism 124. Thesensory portion could be implemented by applying a conductive strip 112on more than one sheet, e.g., but not limiting to the invention,applying a conductive strip 112 on a surface of the glass sheets 22, 24,and 60. As is appreciated, when a conductive strip 112 is placed on morethan one sheet, each one of the conductive strips 112 has its ownelectrical power source 120, or one power source 74 is provided and iselectrically connected to two or more of the conductive strips 112, anda rheostat is provided for each conductive strip 112 for controllingvoltage to each of the conductive strips 112 in a manner discussedabove. In an alternative embodiment of the invention, the sensoryportion of the rupture sensor could be an optical measurement systemmounted separate from the windshield being monitored with the evaluationunit mounted separate from the windshield but electrically connected tothe sensory portion.

Moisture Sensor

As discussed above and as shown in FIG. 2, the windshield ortransparency 14 has an outboard moisture seal or barrier 36 to preventmoisture from entering between the glass sheets 22, 24, and 60, and theplastic interlayers or sheets 26, 28, 30, and 34 of the windshield 14.More particularly, when the moisture seal or barrier 36 fails, e.g.,cracks or de-bonds due to erosion caused by wind and rain, moistureenters between the sheets and/or interlayers of the windshield 14. Whenmoisture moves between the sheets and/or interlayers, the windshield 14can de-laminate and/or the heatable member 32 can be damaged and fail,ending the service life of the windshield. When de-lamination of thewindshield 14 occurs, the rate and amount of moisture entering betweenthe sheets and/or interlayers increases, accelerating the degradation ofthe windshield 14.

With reference to FIG. 9 as needed, the heatable member 32 has moisturesensors 150-153 positioned on the conductive coating 62 adjacent sides82-85, respectively of the sheet 60. As clearly shown in FIG. 10, in onenon-limiting embodiment of the invention, each of the sensors 150-153include a layer 155 of a moisture sensitive material (hereinafter alsoreferred to as “moisture sensitive layer”) deposited on the conductivecoating 62, and an electrically conductive layer 156 deposited on orover the moisture sensitive layer 155. Each of the conductive layers 156of each of the sensors 150-153, as shown in FIG. 11, are individuallyconnected to a positive pole 157 of a power source 158 by way of a wire160 a-160 d, respectively. Optionally, the wires 160 a-160 d areindividually connected to the positive pole 157 of the power source 158through a rheostat or variable transformer 161 to regulate the powerinput to each of the conductive layers 156 of the sensors 150-153.

The invention is not limited to the material of the moisture sensitivelayer 155 and any moisture sensitive material can be used in thepractice of the invention, e.g., but not limited to titanium dioxide,and/or the materials disclosed in U.S. Pat. Nos. 4,621,249 and4,793,175, the disclosures in their entirety are hereby incorporated byreference. Further, the invention is not limited to the material of theelectrically conductive layer 156 on or over the moisture sensitivelayer 155 and any electrically conductive material, e.g., but notlimited to aluminum, copper, gold, and silver, can be used. In one nonlimiting aspect of the invention, a moisture sensitive layer 155includes sputtered titanium dioxide film, and an electrically conductivelayer 156 includes sputtered gold.

As the moisture sensitive layer 155 absorbs moisture, the impedance ofthe moisture sensitive layer 155 changes. As can be appreciated, theimpedance of the moisture sensitive layers 155 can be measured and/ormonitored in any usual manner. In one non-limiting aspect of theinvention, wires 162 a-162 d interconnect the negative pole (−) 159 ofthe power source 158 and the ends of the conductive layers 156 of thesensors 150-153, respectively. The voltage difference between each pairof wires 160 a and 162 a, 160 b and 162 b, 160 c and 162 c, 160 d and162 d is measured and/or monitored by comparator 170 (see FIG. 12). Withreference to FIGS. 11 and 12, the wire 160 a-160 d of each of thesensors 150-153 is connected to comparator 170. The comparator 170monitors the impedance of the moisture sensitive layer 155 of each oneof the moisture sensors 150-153. When the impedance change exceeds apredetermined amount, a signal is forwarded along wire 172 to an alarmand/or monitor discussed below.

In the non-limiting aspect of the invention shown in FIGS. 9-12, thepositive pole (+) 157 of the power source 158 (see FIG. 11) is connectedto the conductive layer 156 of each of the moisture sensors 150-153 bywire 160 a-160 d, respectively, and the negative pole (−) 159 of thepower source 158 is connected to the conductive layer 156 of each of thesensors 150-153 by wires 162 a-162 d, respectively (See FIG. 9).

With the arrangement discussed above, the sensory portion of themoisture sensors 150-153 includes the moisture sensitive layer 155 andthe electrically conductive layer 156, and the evaluation unit of themoisture sensors 150-153 includes the transformer 161 (see FIG. 11) andthe comparator 170 (FIG. 12). The output of the comparator 170 along thewire 172 provides the information as to the performance of the moisturebarrier 36 of the windshield 14. In another non-limiting embodiment ofthe invention, the evaluation unit can consist of a frequency basedimpedance sensor and software monitoring the impedance of the sensor.Again, the invention is a system wherein when the sensing portion of amoisture sensor is included within the windshield, the evaluation unitcan be placed separate from the windshield and electrically monitor thestatus of the moisture sensor. In another non-limiting embodiment of theinvention, the sensory portion of the moisture sensor may be a remote,non-contact device (such as one using infra-red transmission) which mayalso be physically mounted separately from the windshield while stillbeing electrically connected to the evaluation unit separate from thewindshield.

As can now be appreciated, the impact sensor, the rupture sensor, andthe moisture sensor discussed above are designed to operate asnon-activating sensors (discussed above) because they measureperformance of an article to determine if the article is withinacceptable limits and do not automatically take action to alterperformance of the article when the article is performing outside ofacceptable limits.

ARC Sensor and Conductive Coating Temperature Sensor

The discussion is now directed to an arc sensor and a conductive coatingtemperature sensor to monitor the performance of the heatable member 32and take corrective action when the heatable member operates outside ofacceptable limits. More particularly, the arc sensor 72 monitors theperformance of the heatable member 32 to determine if there areoccurrences of major arcing and minor arcing associated with theoperation of the heatable member 32. The conductive coating temperaturesensor 190 monitors the temperature of the heatable member and when thetemperature of the heatable member 32 exceeds a given temperature,switches are activated to disconnect the heatable member from itselectric power source. The arc sensor 72 and the temperature sensor 190are considered together because the electrical circuit for the arcsensor and the electrical circuit for the coating temperature sensorusually operate in conjunction with one another as described below,however, as can be appreciated, the invention contemplates the arcsensor and conductive coating temperature sensor having electriccircuits independent of one another.

In the preferred embodiment of the invention, the arc detection systemis separate from the windshield and included within another avionic unit(such as the heater controller). In this case, both the sensory portionand the evaluation unit are included within the heater controller. Inanother non-limiting embodiment of the invention, the evaluation unit isincluded within the heater controller but the sensory portion isseparate, included within the windshield itself or anywhere along theelectrical connection between the windshield and the heater controller,still being electrically connected to the evaluation unit.

With reference to FIGS. 3 and 13 as needed, temperature sensor 190includes thermistors 188 mounted on the conductive coating 62 to sensethe temperature of the conductive coating 62 of the heatable member 32,and are connected to the intelligent electrical power controller andmonitoring system or arc sensor 72 by a wire or electric cable 192 in amanner discussed below. The invention is not limited to the temperaturesensors 188, and any of the types used in the art can be used in thepractice of the invention. Further, the invention is not limited to thenumber of temperature sensors 188 mounted on the coating 62, and anynumber of sensors, e.g., one, two, or three sensors, can be mounted onthe coating 62 to sense the temperature of different areas of thecoating 62.

It should be noted that FIG. 3 shows three wires 192 for the threetemperature sensors 188, whereas in FIG. 13 the three temperaturesensors and the three wires 192 are bundled and shown as one sensor 188and one wire 192 for purposes of clarity and ease of following the pathof the wires 192.

With reference to FIG. 13, in one non-limiting aspect of the invention,the aircraft power supply 74 supplies alternating electric current alongthe wires 76 and 77 to a window heat controller 197 of the intelligentelectrical power controller and monitoring system or arc sensor 72. Asis appreciated by those skilled in the art, the invention is not limitedto the power supply 74 and the power supply 74 can be an alternatingcurrent supply as shown in FIG. 13 or a direct current supply as isknown in the art and shown in FIG. 5. The wire 76 of the power supply 74is connected to one pole of a switch 198 of the window heat controller197, and the other pole of the switch 198 is connected to currenttransformer 199 of an arc monitoring and detecting system 200 of theinvention by a wire or electric cable 202. The switch 198 is usually inthe closed position and is moved from the closed position to the openposition and vice versa by signals forwarded along wire or electriccable 204 from a control logic for a heat controller 206 of the windowheat control 197. The current transformer 199 is connected to the busbar 66 of the heatable member 32 by the wire 70. The bus bar 68 of theheatable member 32 is connected to the power supply 74 by the wires 71and 77.

In one non-limiting aspect of the invention, components of theintelligent electrical power controller and monitoring system or arcsensor 72 are mounted in a Faraday box 209, and the Faraday box 209 isconnected to ground, e.g., the body 87 of the aircraft 10 (see FIG. 1)by the wire or cable 211 (see FIG. 13) to block out external staticelectric fields.

With continued reference to FIG. 13, the temperature sensor 188 isconnected to one connector of an electronic switch 210 by the wire 192,and a second connector of the switch 210 is connected by wire 212 to thecontrol logic 206 of the window heat controller 197. The switch 210 isusually in the closed position and is moved from the closed position tothe open position, and from the open position to the closed position, bysignals forwarded to the switch 210 along wire or electric cable 214from a signal filtering and modifying system 216 of the arc monitoringand detecting system 200.

The evaluation unit 216 of the arc sensor 72 provides a signal to switch210 for electrically disconnecting the heating arrangement 32 and thepower supply 74 from one another when any of the following conditionsare detected: (a) the temperature of the heatable member 32 is greaterthan a predetermined temperature; or (b) major arcing.

Consider now Condition (a): the temperature of the heatable member 32 isgreater than a predetermined temperature. With reference to FIG. 13, theswitch 198 of the heat controller 197 and the switch 210 are each in theclosed position to heat the heatable member 32 to remove fog, snow,and/or ice from the outer surface 46 of the windshield 14 (see FIG. 2).The temperature of the heatable member 32 is sensed by the temperaturesensor 188 and the signal of the temperature sensor 188 is monitored bythe evaluation unit 206 of the window heat controller 197. When thetemperature of the heatable member 32 exceeds a given temperature, e.g.,but not limiting to the discussion because of arcing or an increase inthe resistance of the coating 62, the heat controller 206 forwards asignal to the switch 198 along the cable 204 to open the switch 198 toelectrically disconnect the power supply 74 and the heatable member 32from one another. The invention is not limited to the cause of theheatable member 32 exceeding the predetermined temperature and any typeof defect of the heatable member 32 that caused the predeterminedtemperature to be exceeded is included in the practice of the invention.

The discussion is now directed to a non-limiting aspect of the signalmonitoring and detecting system 200 of the arc sensor 72. The arcmonitoring and detecting system 200 is designed to detect and act onarcing, namely condition (b). Condition (b) is termed “major-arcing” andis defined as measured voltage/current exceeding a first predeterminedlevel of voltage/current. The value of the first predetermined level isnot limiting to the invention, and the value is selected such thatarcing is visible with the unaided eye and/or based on prior experiencecan damage the window 14. In one non-limiting embodiment of theinvention, the first predetermined level of voltage/current is based onthe model of the window and the current needed to heat the window toremove fog, snow, and ice, and to prevent the formation of fog, snow,and ice, on the outer surface 43 of the window 14.

Consider now the case when there is major arcing without the temperatureexceeding the predetermined temperature. The arc monitoring anddetecting system 200 detects major arcing and forwards a signal to thesignal modifying system 216. The signal modifying system 216 forwards asignal along the wire 214 to open the switch 210. The control logic fora heat controller 206 determines that the switch 210 is in the openposition and sends a signal along the cable 204 to open the switch 198to electrically disconnect the power supply 74 and the heatable member32 from one another. As can be appreciated by those skilled in the art,when there is major-arcing and the temperature of the heatable member 32exceeds the predetermined temperature, the switch 210 and/or the switch198 are opened.

Another type of arcing is known in the art as “micro-arcing” and isdiscussed in U.S. Pat. Nos. 9,166,400 and 8,981,265.

The discussion is now directed to a non-limiting aspect of the arcmonitoring and detection system 200. The arc monitoring and detectionsystem 200 is designed to, among other things, detect major-arcing, andtake action to prevent or limit damage to the heatable member 32 and/orthe window 14. The switch 198 and the switch 210 (see FIG. 13) are ofthe type that open and close in response to signals forwarded to theswitch. In the practice of the invention, the switch 198 is anelectronic solid state switch. The control logic for a heat controller206 of the window heat controller 197 is a comparator of the type thatcompares the electrical signal, e.g., in mV from the temperature sensor188 to a set voltage range, and when the signal is outside of the range,the control logic of the heat controller 206 forwards a signal to openthe switch 198, and when the signal is within the range, the controllogic for a heat controller 206 sends a signal along the wire 204 toclose the switch 198.

With reference to FIG. 14, the discussion is now directed to the arcdetecting and monitoring system or arc sensor 200 to detect major andoptionally micro-arcing, and take action to prevent or minimize damageto the heatable member 32 and/or the window 14 (see FIGS. 2 and 3). Asshown in FIGS. 13 and 14 as needed, the current transformer 199 isconnected to the wires 202 and 70, and the output of the transformer 199passed onto the filter 248 by the wires 250. The invention is notlimited to the type of transformer 199 used in the practice of theinvention. In the preferred practice of the invention, the currenttransformer 199 was of the type to reduce the current to a lower levelfor ease of filtering the current moving along the wires 202 and 70.More particularly, the current transformer 199 produces a reducedcurrent accurately proportional to the current passing through the wires202/70 to the heatable member 32. For example, in one non-limitingembodiment of the invention, the current passing through the heatablemember 32 was 18.5 amperes and the output of the current transformer 199was 1.85 amperes.

With continued reference to FIG. 14, signal filter 248 of the signalfiltering and modifying system 216 is a high pass filter to effectivelyeliminate electrical and magnetic noises from the signals passing alongthe wire 250. The filter level of the signal filter 248 is based onnoise spectral analysis of the electrical system, i.e., the currentpassing from the power supply 74 to the heatable member 32. The filter248 also reduces the magnitude of the line signal due to elimination ofthe high frequency component, e.g., but not limiting to the invention by2 levels.

The signal from the signal filter 248 is passed onto a two stage filter254. The first stage filter 254A includes a comparator to filter outsignals having voltage/current levels above the first predeterminedlevel, e.g., 150 mV indicating major arcing. When the signal of thefirst stage filter 254A exceeds the first predetermined level, the timethat the signal exceeds that first predetermined level is counted by254B. Once the time counted in 254B exceeds a certain predeterminedquantity, a signal is sent along wire 256 to signal switch 257 thatmajor arcing has been detected, and the signal switch 257 sends a signalalong the wire 214 to open the switch 210, which causes the controllogic for the heat controller 206 to open the switch 198 (see FIG. 13)to prevent the current from moving from the power supply 74 to theheatable member 32 as discussed above.

With continued reference to FIG. 14, the signal filter 248 and the dualfilter 254 are each connected by wires 258 and 260, respectively, to amicro-computer 264. Optionally, the micro-computer 264 is connected toan electronic storage 266 of the aircraft by wire or cable 268. Themicro-computer 264 sets the level, e.g., the second predetermined levelfor the filter 248, to filter the noise from the signal from the currenttransformer 199, sets the level, e.g., the first predetermined level forthe filter 254A to identify major-arcing. The electronic storage 266maintains a history of the activities of the filter 248 and two stagefilter 254 to provide data for setting the predetermined first levelindicating micro-arcing, the second predetermined level indicating noiselevel in the signal from the transformer 199, and the micro arc countand time period to indicated a potential problem due to micro-arcing.

With the arrangement discussed above, the sensory portion of the coatingtemperature sensor 190 is a thermistor 270, however the invention is notlimited to the type of temperature sensing technology and could beinfrared monitoring, a thermocouple, etc. As can be appreciated, theinvention can be practiced with more or less than four temperaturesensor sensory portions 190. More particular, increasing the number oftemperature sensor sensory portions, e.g., using 5, 6, 7, 10, or 20temperature sensor sensory portions, increases the accuracy ofmonitoring the distributed temperature, and using less than 4, e.g., 1,2, 3 sensors, decreases the accuracy monitoring the distributedtemperature. For purposes of clarity, the sensory portion of the coatingtemperature sensor 190 is identified by the number 267. The evaluationunit of the coating temperature sensor 190 is the heat controller 197and the switch 210. For purposes of clarity, the evaluation unit of thecoating temperature sensor 190 is identified by the number 270.

The sensory portion of the arc sensor 72 is the current transducer 199.The evaluation unit of the arc sensor 72 is the circuit designed by thenumber 200 in FIG. 14.

From the above discussion and arrangement of the coating temperaturesensor and the arc sensor, it can be appreciated that the coatingtemperature sensor 190 and the arc sensor are generally consideredactivating sensors (discussed above) because they are performancemonitoring and action taking sensors. More particularly, when theconductive coating 62 of the heatable member 32 exceeds a desiredtemperature, the switch 210 automatically acts to arrange a disconnectbetween the electric power, e.g., the electric power source 74, and theheatable member 32, and when the arc monitoring and detecting system 200determines that there is excessive arcing, the arc monitoring anddetection system acts on the window heat controller 197 to arrange adisconnect between the electric power, e.g., the electric power source74 and the heatable member 32.

As can now be appreciated, the invention is not limited to the impactsensor, the rupture sensor, the moisture sensor, the arc sensor, and theconductive coating temperature sensor discussed above, and is directedto any type of sensor, for example also includes, but is not limited tostatic sensors, vibration sensors, and transmission sensors. Further,but not limiting to the invention, the evaluation unit of the sensorsare the electronics and can be classified as the portion of the sensorthat acts on the signals from the sensory portion of the sensor todetermine the operating performance of the component being monitored,e.g., but not limited to the windshield 14. The sensory portion is theportion of the sensor that measures properties of a component, e.g., butnot limited to the windshield 14, and is monitored by the evaluationunit of the sensor to make changes to the sensory portion. Stillfurther, the invention contemplates an active computer memory to storethe information from the window sensor system both in real time andhistory, e.g., but not limited to the electronic storage 266 shown inFIG. 14. As can be appreciated by those skilled in the electronicstorage art, the electronic storage 266 can include, but is not limitedto, an electronics circuit structure that can support multi-input andmulti-output sensor system; an embedded micro-computer that can beprogrammed to perform intelligent solution based on a mathematical modelframe work, and/or communication capability to electronically transmitthe window status/conditions to the aircraft center diagnosis computersystem.

Present Practice for Mounting Sensors to Windshields

The subject matter of interest to the present discussion is the presentpractice to position the sensory portion, and the evaluation unit of thesensors on the aircraft window. In the following discussion, the sensorsare monitoring an aircraft windshield. The invention, however, is notlimited thereto, and the invention can be practiced on any type ofvehicle window.

The electric power supply to operate the sensors is not generallymounted on the windshield, but is mounted on the aircraft and connectedin any convenient manner to sensors mounted on the windshield. As can beappreciated, electric power in the form of small size battery, e.g., Dtype, C type, double A type, triple A type, and/or disc type battery,can be mounted on the windshield. In the following discussion of thenon-limiting aspect of the invention, the electric power supply isprovided by an electric source, e.g., power source 74, mounted on theairplane and connected to the windshield in any convenient the manner.

Shown in FIG. 15 is a plan view of a portion of a currently availablewindshield showing only the glass sheet 60, the conductive coating 62,the bus bars 66 and 68 (see FIG. 2), and the sensory contacts of theimpact sensor, the rupture sensor, the moisture sensor, the arc sensor,and the conductive coating temperature sensor. FIG. 16 is a view of thewindshield of FIG. 15 showing the evaluation units of the impact sensor,the rupture sensor, the moisture sensor, the arc sensor, and theconductive coating temperature sensor mounted on the surface 42 of theglass sheet 22 (see FIG. 2) of the windshield 14 facing the interior ofthe aircraft 10 (see FIG. 1). With continued reference to FIG. 15, thereis shown the piezoelectric crystals 91 a-91 d of the impact sensors 89a-89 d (see FIGS. 4 and 5) connected to the wires or electricalconductors 95 a-95 d. The electric conductor strip 112 of the rupturesensor 110 (see FIGS. 6 and 8) having the leads or electrical conductor126 and 128 connected to the first and second terminal surfaces 116 and118, respectively, and the lead 130 to provide contact to the electricalpower system 74 or 120 (see FIG. 6) as discussed above. The electricallyconductive layer 156 of the moisture sensors 150-153 having the wires orelectrical conductors 160 a-160 d to one end of each of the fourelectrically conductive layers 156 and the wires or electricalconductors 162 a-162 d connected to the opposite end of the fourelectrically conductive layers 156 (see FIGS. 9-11) as discussed above.As shown in FIGS. 15 and 16, the three conductive coating temperaturesensors 188 are mounted on the conductive coating 62 (see also FIGS. 13and 14) to measure the temperature of the conductive coating 62.

With reference to FIG. 16, mounted, preferably securely mounted on theinner surface 42 of the windshield 14 as mounted on the aircraft body 87(see FIG. 1), are electrical connectors 280 and 282 to provide externalelectrical access to selected sensors, and/or to provide electricalpower input to operate the evaluation unit and/or the sensory portion.The connector 280 has an integrated circuit or an electronic chip of theevaluation unit of the impact sensors 89 a-89 d designated by the number284; of the evaluation unit of the rupture sensor 110 and/or 111designated by the number 286, and of the evaluation unit of the moisturesensors 150-153 designated by the number 288. As can be appreciated, theinvention is not limited to the number or types of sensors describedabove.

The electronic chips 284, 286, and 288 are connected to connection area290 of the connector 280. The connection area 290 of the connector 280functions as a connection to an electric power supply, e.g., but notlimited to wire 302, interconnecting the electric current supply 74 andthe impact, rupture, and moisture sensors to power the evaluation unitsof the impact, rupture, and moisture sensors. Wire 304 is a connectionfor passing electric signals to alter the settings of the sensoryportion and/or the evaluation unit of the impact, rupture, and moisturesensors under discussion, and as a passageway, e.g., but not limited toa passageway along the wire 304 to the electronic storage unit 266 (seeFIGS. 14 and 16), to collect and store data in the electronic storageunit 266 provided by the impact, rupture, and moisture sensors.

With continued reference to FIG. 16, the connector 282 securely mountedon the inner surface 42 of the windshield 14 has a chip 292 of theevaluation unit 270 of the coating temperature sensor 190, a chip 294 ofthe evaluation unit of the arc sensor 72, and a connection area 296. Inanother non-limiting embodiment of the invention, all the sensoryportions are monitored and evaluated by a single evaluation unit. Wire312 connects the connector 282 to an electric power supply, e.g., theelectric current supply 74, and connects the arc sensor 72, and thecoating temperature sensor 190 to the current supply to power theevaluation units 274 of the arc sensor 72 and the coating temperaturesensor 190. The wire 304 of the connector 282 is a connection forpassing electric signals to alter the setting of the sensory portion 272and/or the evaluation unit of the of the arc sensor and the coatingtemperature sensor, and as a passageway, e.g., but not limited to apassageway along the wire 304 to the electronic storage unit 266 (seeFIGS. 14 and 16), to collect and store data generated by the arc sensorand the coating temperature sensor.

The invention is not limited to the chip or integrated circuit, and anyof the chip and integrated circuit technology known in the art can beused to provide the evaluation unit of the impact sensor, the rupturesensor, the moisture sensor, the arc sensor, and the coating temperaturesensor to an electronic chip or integrated circuit. Further, convertingthe evaluation unit of the impact sensor, the rupture sensor, themoisture sensor, the arc sensor, and the temperature sensor to anelectronic chip is well known in the art and no further discussion isdeemed necessary.

The cable 192 of the temperature sensors 188 (shown bundled in FIG. 13)are connected to the electronic chip 292. The electronic chip 292includes the switch 210 (see FIG. 13) and electronic circuit to measurethe temperature of the coating 62 and to act on the switch 210 asdiscussed above. The chip 294 includes the evaluation unit of the arcsensor, and is connected to the switch 210 to open and close the switch210 as discussed above.

The electronic chips 292 and 294 are connected to the connection area296 of the connector 282. The connection area 296 provides a connectionto an electric power supply, e.g., but not limiting to the invention,wire 312 interconnects the electric current supply 74, and thetemperature sensor and arc sensor to power the evaluation unit andsensory portion of the temperature sensor and of the arc sensor.

As can now be appreciated, it is the present practice to mount thesensory portion, and the evaluation unit, of the sensors on the samewindow, e.g., the same windshield.

Non-Limiting Aspects of the Invention

In a non-limiting aspect of the invention, sensors each having a sensoryportion and an evaluation unit is provided (see above discussion). Thesensory portion of the sensors is mounted in the construction of avehicle window, e.g., an aircraft windshield as discussed above, and theevaluation unit of the sensor is not mounted on the aircraft windshieldwith the sensory portion of the sensor, but is mounted elsewhere, e.g.,but not limiting to the invention, in a cabinet mounted in the aircraftfor storage of electrical circuit boards, and/or on the body of theaircraft and/or in a geographic area outside of the aircraft. Theinvention further contemplates mounting the evaluation unit of the arcsensor outside of the aircraft and having wireless communication betweenthe sensory portion and the evaluation unit of the sensor. By way ofillustration and not limiting to the invention, the evaluation unit ofan arc sensor can be maintained in a central control area in a specifiedgeographical area, and communications with the sensory portion of thearc sensor can be by wireless communication, e.g., as disclosed in U.S.Pat. No. 8,383,994, which patent in its entirety is hereby incorporatedby reference. Wireless communication is well known in the art and in nofurther discussion is deemed necessary.

Shown in FIG. 17 is a non-limited aspect of a windshield of theinvention identified by the number 320. The windshield 320 is similar tothe windshield 14 shown in FIG. 16 except that the evaluation unit 93a-93 d of the impact sensors 89 a-89 d, respectively; the evaluationunit 122 of the rupture sensor 110 (FIG. 6) and/or 111 (FIG. 8); theevaluation unit 170 of the moisture sensors 150-153; the evaluation unit270 of the coating temperature sensor 190, and the evaluation unit 274of the arc sensor 72 are not mounted on the windshield; they are mountedin a cabinet 330 shown in FIG. 17 and located on the airplane 10.Although not limiting to the invention, in one non-limiting aspect ofthe invention, the evaluation units are mounted in the cabinet 330 withthe window heat controller 197 and the electronic storage 266. Theelectric power supply 74 is connected to the evaluation units 93 a-93 d,122, 170, 270, and 2274, to the heat controller 197, and to theelectronic storage 266, in the cabinet 330 by the wires 76 and 77 in themanner discussed above. In another non-limiting aspect of the invention,the evaluation units and electronic storage are mounted within thewindow heater controller itself.

In another non-limiting aspect of the invention, the electric circuitfor the evaluation unit of the arc sensor and the evaluation unit of thecoating sensor can share electric components as shown in FIGS. 13 and14. Further, the electric circuit for the elevation unit of the arcsensor, the evaluation unit of the coating sensor, and the heatcontroller 197 can share electric components as shown in FIGS. 13 and14.

With reference to FIG. 16, the connectors 280 and 282 are shown havingthe evaluation units in FIG. 16 replaced in FIG. 17 by one or moreconnection areas that do not have the evaluation units of the sensors.More particularly, in one non-limiting aspect of the invention, theevaluation unit 93 a-93 d of the impact sensor 89 a-89 d is connected towire 350; the evaluation unit 170 of the rupture sensor 122 is connectedto wire 352, and the evaluation unit 170 of the moisture sensor 150-153is connected to wire 354, and the wires 350, 352 and 354 bundled(identified by the number 356), and the bundled wire 356 electricallyconnected to connection area 360 of connector 362. The evaluation unit270 of the coating temperature sensor 190 is connected to the wire 362,the evaluation unit 274 of the arc sensor 72 is connected to the wire364, and the wires 362 and 364 are bundled (identified by the number366), and the bundled wire 366 electrically connected to connection area370 of connector 372.

The electronic storage 266 is electrically connected to the evaluationunit within the cabinet 330. Wires 376 and 378 are connected within thecabinet 330 to the electrical power supply 74 by way of wires 76 and 77and at the opposite end to the connection area 370 of the connector 372.Internal wires (not shown) of the windshield 320 connect the wires 376and 378 in the connection area 370 to the wires 79 and 80 connected tothe bus bars 66 and 68. As can be appreciated, the invention is notlimited to the manner in which the wires are connected to the connectionareas 360 and 370 of the connectors 362 and 372, respectively, and anytype of connection can be used to secure the connection, e.g., and notlimiting to the invention, the connection can be a connection having ahole and a bayonet insert.

As can now be appreciated, the evaluation units are removed from thewindshield 14 to a cabinet 330 having in one aspect of the invention thewindow heat controller 197 and the electronic storage 266. The inventionalso contemplates the positioning of evaluation unit of one or moresensors, e.g., the evaluation units 93 a-93 d, 122 and 170 in connectorsmounted on the inner surface of the windshield as shown in FIG. 16, andthe positioning of the evaluation units 270 and 274 in the cabinet 330.

With reference to FIG. 18, in another non-limiting aspect of theinvention, the evaluation units are mounted in a housing 400 mounted inthe interior of the airplane. Also mounted in the housing 400 is acomputer 402 having a health monitoring system of the airplane 10. Thehousing 400 can further include a speaker and/or an alarm 408 to provideaudible information regarding the performance of aircraft componentsbeing monitored.

In another non-limiting aspect of the invention, both the sensoryportion and the evaluation unit of a sensor can be mounted in thehousing 400 when the sensory portion does not require a measuringelement. As a non-limiting example, the current transducer 199 (FIG. 14)can be mounted anywhere on the windshield power line, e.g., but notlimited to power lines 70, 76 or 71, 77, connected to bus bar 66 or busbar 68, respectively, at a location within the windshield heatercontroller 197. In this case, the windshield can have no measuringelement or no embedded sensory portion of the sensor, but still obtainactive sensor response through the use of the arc sensor sensory portionand evaluation unit within the heater controller.

More particularly, the sensory portion of the arc sensor monitors thecurrent moving through the power lines 70, 76, or 71, 77 and the busbars 66 and 68, and forwards a signal to the evaluation unit of the arcsensor to determine if there is arcing. The sensory portion of the othersensors, e.g., the rupture sensor, the impact sensor, a moisture sensor,and temperature sensor, includes the use of one or more measuringelements. For example and not limiting to the discussion, the sensoryportion of the rupture sensor has a conductive strip 112 (see FIG. 6) onthe heatable member 32. The conductive strip 112 forwards a signal tothe evaluation unit of the rupture sensor to monitor the performance ofthe windshield. With the above arrangements, it can be appreciated thatthe sensory portion of the arc sensor only requires an electricalconnection to the power lines or bus bars to monitor the performance ofthe heatable member 32 and, therefore, the electrical connection can bemade to the electric circuit of the heatable member, which includes butis not limited to an electrical connection to the heater controller 197.

As can now be appreciated, the evaluation unit of the sensor can becontained in one circuit, e.g., but not limiting to the invention, onecircuit board, or can be on two or more circuit boards. By way ofillustration and not limiting to the invention, the heat controller 197(FIG. 13) and the evaluation unit 274 of the arc sensor 72 can be on onecircuit board (see FIG. 17) and the remaining components of theevaluation unit of the arc sensor can be on another circuit board asshown in FIG. 17.

Further, the invention is not limited to the aspects of the inventionpresented and discussed above which are presented for illustrationpurposes only, and the scope of the invention is only limited by thescope of the following claims and any additional claims that are addedto applications having direct or indirect lineage to this application.

What is claimed is:
 1. A windshield monitoring system, comprising: awindshield comprising a heating arrangement for removing fog, ice,and/or snow from the windshield, the heating arrangement comprising apair of spaced bus bars and an electrically conductive coating coveringat least a portion of the windshield extending between and in electricalcontact with the spaced bus bars; a cabinet configured to store one ormore electronic devices spaced apart from and in electrical contact withthe windshield via at least one power line; a power supply electricallyconnected to the windshield through the at least one power line, thepower supply being configured to provide electrical current through thebus bars and through the electrically conductive coating to heat theelectrically conductive coating, thereby heating at least an outersurface of the windshield; and an arc sensor comprising a sensoryportion electrically connected to and configured to detect voltage orcurrent of a signal passing through the at least one power line from oneof the bus bars and an evaluation unit in the cabinet configured todisconnect the power supply from the heating arrangement based on thevoltage or current detected by the sensory portion of the arc sensor. 2.The windshield monitoring system of claim 1, wherein the windshield is awindshield of a vehicle, and wherein the cabinet is located in thevehicle.
 3. The windshield monitoring system of claim 1, furthercomprising at least one parameter sensor for measuring a parameter ofthe windshield, the at least one parameter sensor comprising a sensoryportion in physical contact with the windshield and an evaluation unitin the cabinet, wherein the at least one parameter sensor is selectedfrom a group of an impact sensor, a rupture sensor, a moisture sensor, astress sensor, a temperature sensor, and a p-static sensor.
 4. Thewindshield monitoring system of claim 1, wherein the evaluation unit ofthe arc sensor is configured to disconnect the power supply from the busbar when the detected voltage or current indicates an increase in aresistance of the conductive coating of the heating arrangement.
 5. Thewindshield monitoring system of claim 1, further comprising at least onetemperature sensor comprising a sensory portion connected to thewindshield configured to generate a signal representative of atemperature of at least a portion of the windshield and the evaluationunit in the cabinet configured to act on the signal generated by thesensory portion of the temperature sensor.
 6. The windshield monitoringsystem of claim 5, further comprising a first switch electricallyconnecting the power supply to one of the bus bars of the heatingarrangement, wherein the first switch in a closed position provides acontinuous electrical path from the power supply through the firstswitch to the conductive coating and the first switch in an openposition electrically separates the power supply from the conductivecoating, and wherein the evaluation unit of the at least one temperaturesensor is configured to cause the first switch to open when the signalgenerated by the sensory portion of the at least one temperature sensorindicates that the temperature of the windshield exceeds a predeterminedtemperature.
 7. The windshield monitoring system of claim 6, furthercomprising a second switch electrically connecting the sensory portionof the at least one temperature sensor to the cabinet, wherein thesecond switch in a closed position electrically interconnects the atleast one temperature sensor and the cabinet, and in an open positiondisconnects the cabinet and the at least one temperature sensor, andwherein the evaluation unit of the arc sensor is configured to operatethe second switch to transition the second switch from the closedposition to the open position when the detected voltage or current ofthe electrical signal passing through the at least one power lineexceeds a predetermined value.
 8. The windshield monitoring system ofclaim 7, wherein, with the first switch and the second switch in theclosed positions, a first electric path is provided from the powersupply through the first switch to the heating arrangement of thewindshield, and a second electrically conductive path is provided fromthe sensory portion of the at least one temperature sensor, through thesecond switch, to the cabinet.
 9. The windshield monitoring system ofclaim 5, wherein the sensory portion of the at least one temperaturesensor comprises a thermistor mounted to the conductive coating.
 10. Thewindshield monitoring system of claim 1, wherein the sensory portion ofthe arc sensor comprises a current transformer electrically connected tothe at least one power line, and wherein the current transformer isconfigured to reduce the electrical signal passing through the powerline to a reduced magnitude signal for improved filtering of theelectrical signal passing from the bus bar to the power supply.
 11. Thewindshield monitoring system of claim 10, wherein the reduced magnitudesignal output by the current transformer is proportional in magnitude toan electrical current passing from the power supply to the conductivecoating.
 12. The windshield monitoring system of claim 10, wherein thereduced magnitude signal output by the current transformer is passed toa high pass filter which filters the signal to reduce or eliminateelectrical or magnetic noises from the signal.
 13. The windshieldmonitoring system of claim 1, wherein the evaluation unit of the arcsensor is configured to compare the voltage or current detected by thesensor portion of the arc sensor to a predetermined value, determine anamount of time that the detected voltage or current exceeds thepredetermined value, and determine that major arcing is occurring whenthe determined amount of time exceeds a predetermined time value. 14.The windshield monitoring system of claim 1, further comprising anelectronic storage device mounted in the cabinet, wherein the electronicstorage device is configured to collect and store data received from theevaluation unit of the arc sensor.
 15. The windshield monitoring systemof claim 14, wherein the evaluation unit of the arc sensor is configuredto receive performance history information for the conductive coatingfrom the electronic storage device.
 16. The windshield monitoring systemof claim 1, wherein the windshield comprises at least one first sheet,at least one second sheet, and at least one interlayer disposed betweenthe at least one first sheet and the at least one second sheet.
 17. Anaircraft comprising the windshield monitoring system of claim 1 and anaircraft body comprising an interior, wherein the windshield is mountedto the body and the cabinet is positioned in the interior of theaircraft body.